Hi Jeff ,
These messages mean that "Someone" is logged into the SRX in cofiguration private mode.
You will not be able to commit any changes to the configuration unless you are logged in privately as well.
This is a normal message, and the only thing that you can do is make sure that either you are logged in private or that you are the only person logged into the box at that time. ( A solution at your case is to reboot the box )
Configure private allows more than one user to be logged in and make changes withoug affecting another users changes. This means that if one user is logged in configuration private all subsecquent users must log in configuration private.
Configure exclusive only allows one user to be making changes at a time. This means that only one user can be in configuration mode at a time.